IX ASSIGNMENT : SURFACE AREA AND PRESSURE & THRUST

IX TEST- SURFACE AREA & VOLUME AND PRESSURE & THRUST

1.       [2] The volume of a cuboid is 840 cm³. If its length is 14 cm and breadth is 5 cm. Find the height of cuboid?

2.       [2] Four equal cubes have side 5 cm each. They are joined together edge to edge. What will be the surface area of cuboid thus formed?

3.       [2] The total volume of a cube is 512 cubic cm. Find the side of a cube?

4.       [2] A rectangular box 14 cm long, 10 cm wide and 5 cm high is to be made with card-board. Find the area of card-board to make that box

5.       [2] The length, breadth and height of a room are 12 m, 10 m, and 9m respectively. Find the area of  four walls of room?

6.       [2] How much Aluminium sheet will be required to make a container with lid whose length is 13 m, breadth is 8 m and height is 4 m?

7.       [2] The floor of a rectangular hall has a perimeter 250 m If the cost of painting the four walls at the rate of Rs 10per m² is Rs 15000, find the height of the hall. 

8.       [2] Hameed has built a cubical water tank with lid for his house, with each outer edge 1.5 m long. He gets the outer surface of the tank excluding the base, covered with square tiles of side 25 cm. Find how much he would spend for the tiles, if the cost of the titles is Rs 360 per dozen. 

9.       [2] A small indoor greenhouse (herbarium) is made entirely of glass panes (including base) held together with tape. It is 30 cm long, 25 cm, wide and 25 cm high.  (i) What is the area of the glass?   (ii) How much of tape is needed for all 12 edges? 

10.    [2] A river 3m deep and 40m wide is flowing at the rate of 2km per hour. How much water will fall into the sea in a minute? 

11.    [2] A solid cube of side 12 cm is cut into eight cubes of equal volume. What will be the side of the new cube? Also, find the ratio between their surface areas.

12.    [2] In what direction does the buoyant force on an object immersed in a liquid act?

13.    [2] Why does a block of plastic released under water come up to the surface of water?

14.    [2] The volume of 50 g of a substance is 20 cm³. If the density of water is 1 g cm⁻³, will the substance float or sink?

15.    [2] The volume of a 500 g sealed packet is 350cm³. Will the packet float or sink in water if the density of water is 1 g cm⁻³? What will be the mass of the water displaced by this packet?

16.    [2] A cube of mass 1kg with each side of 1cm is lying on the table. Find the pressure exerted by the block on the table. take g=10 m/s²

17.    [2] The density of turpentine oil is 840 Kg/ m³. What will be its relative density. (Density of water  is 1000 Kg /m³)

18.    [2] A solid body of mass 150 g and volume 250cm3 is put in water . will following substance float or sink if the density of water is 1 gm-3?

19.    [2] A body weighs 50 N in air and when immersed in water it weighs only 40 N. Find its relative density.